RE: [PATCH net] net: hns: Fix the device being used for dma mapping during TX

[Salil Mehta]

> -----Original Message-----
> From: YUAN Linyu [mailto:Linyu.Yuan@xxxxxxxxxxxxxxxxxxxx]
> Sent: Thursday, February 09, 2017 9:36 AM
> To: Salil Mehta; davem@xxxxxxxxxxxxx
> Cc: Zhuangyuzeng (Yisen); mehta.salil.lnk@xxxxxxxxx;
> netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; Linuxarm;
> Yankejian (Hackim Yim)
> Subject: RE: [PATCH net] net: hns: Fix the device being used for dma
> mapping during TX
> 
> 
> 
> > -----Original Message-----
> > From: netdev-owner@xxxxxxxxxxxxxxx [mailto:netdev-
> owner@xxxxxxxxxxxxxxx]
> > On Behalf Of Salil Mehta
> > Sent: Thursday, February 09, 2017 5:24 PM
> > To: davem@xxxxxxxxxxxxx
> > Cc: salil.mehta@xxxxxxxxxx; yisen.zhuang@xxxxxxxxxx;
> > mehta.salil.lnk@xxxxxxxxx; netdev@xxxxxxxxxxxxxxx;
> > linux-kernel@xxxxxxxxxxxxxxx; linuxarm@xxxxxxxxxx; Kejian Yan
> > Subject: [PATCH net] net: hns: Fix the device being used for dma
> mapping during
> > TX
> >
> > From: Kejian Yan <yankejian@xxxxxxxxxx>
> >
> > This patch fixes the device being used to DMA map skb->data.
> > Erroneous device assignment causes the crash when SMMU is enabled.
> > This happens during TX since buffer gets DMA mapped with device
> > correspondign to net_device and gets unmapped using the device
> > related to DSAF.
> >
> > Signed-off-by: Kejian Yan <yankejian@xxxxxxxxxx>
> > Reviewed-by: Yisen Zhuang <yisen.zhuang@xxxxxxxxxx>
> > Signed-off-by: Salil Mehta <salil.mehta@xxxxxxxxxx>
> > ---
> >  drivers/net/ethernet/hisilicon/hns/hns_enet.c |    2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/net/ethernet/hisilicon/hns/hns_enet.c
> > b/drivers/net/ethernet/hisilicon/hns/hns_enet.c
> > index 672b646..2b52a12 100644
> > --- a/drivers/net/ethernet/hisilicon/hns/hns_enet.c
> > +++ b/drivers/net/ethernet/hisilicon/hns/hns_enet.c
> > @@ -305,7 +305,7 @@ int hns_nic_net_xmit_hw(struct net_device *ndev,
> >  			struct hns_nic_ring_data *ring_data)
> >  {
> >  	struct hns_nic_priv *priv = netdev_priv(ndev);
> > -	struct device *dev = priv->dev;
> > +	struct device *dev = ring_to_dev(ring_data->ring);
> >  	struct hnae_ring *ring = ring_data->ring;
> struct device *dev = ring_to_dev(ring); ??????
Yes, name of the macro is slight misnomer but this gets the dsaf device.
Hope this answers your question?

Thanks
Salil
> >  	struct netdev_queue *dev_queue;
> >  	struct skb_frag_struct *frag;
> > --
> > 1.7.9.5
> >